Mechanics

CHEVY CHECK ENGINE LIGHT

2007 Chevrolet Aveo

Engine Performance problem
2007 Chevy Aveo 4 cyl Front Wheel Drive Automatic 41,000 miles

My Daughters Aveo's check engine light just came on and is hard to start sometimes and runs rough. I took it to Auto Zone to have it read and the read out did not list a real fix to the problem. They did look up some possibilities to the problem but were not sure where the problem might be. They were looking at either the fuel pump relay or the A/C relay as the problem. The A/C has not been cooling the car very well over the summer and is just blowing cool air on max A/C. Do you have any thoughts on what the problem might be? She does have regular maintenance done on the vehicle.
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Cbvet57
September 22, 2010.



Hello,

Thank You for the Donation.

If you have the print out they may have done post the codes and I will decipher and give you possible causes and test proceedures.

.

Obxautomedic
Sep 22, 2010.
Hi! Thanks for your quick responce.
The troubleshooting code is P0446 for OEM Brand Domestic. The definition given on the print out is EVAP (evaporation emmission system) purge/vent
solenoid circuit condition
Explanation
The solenoids & system wiring are monitored for opens or shorts
Probable cause
Purge or vent solenoids defective
Check connector & wiring
Fuel saturated vapor canister
Failed EVAP vent solenoid

Thats all that is on the print out. Hope you get get something from it.

Bob

Tiny
Cbvet57
Sep 22, 2010.
Ok, I know the below info me be a bit much for you to handle since there are some special tools need....

However, the one thing you can do is look at the diagram of the EVAP System follow it and check for Kinks, remove if possible and check for blockages....

If you feel you can do most of the below and would like for me to post most testing for the evap solenoid and all let me know....

DTC P0446

DIAGNOSTIC INSTRUCTIONS

•Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
•Strategy Based Diagnosis
•Diagnostic Procedure Instructions

DTC DESCRIPTOR

Evaporative Emissions (EVAP) Vent System Performance

CIRCUIT/SYSTEM DESCRIPTION

CONDITIONS FOR RUNNING THE DTC

â—¦The start-up intake air temperature (IAT) and the start-up engine coolant temperature (ECT) are within 8 °C (46 °F).

A restricted or blocked evaporative emission (EVAP) vent path is detected by the control module commanding the purge valve ON (open) and the vent valve ON (closed) allowing a vacuum to be applied to the EVAP system. Once a calibrated vacuum level has been reached, the control module commands the purge valve OFF (closed) and the vent valve OFF (open) while monitoring the fuel tank pressure (FTP) sensor for a decrease in vacuum. If the vacuum does not decrease to near 0 inches H2O in a calibrated time, DTC P0446 will set.

•DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0300, P0402, P0404, P0405, P0406, P0443, P0451, P0452, P0453, P0454, P0461, P0462, P0463, P0464, P0488, P0498, P0499, P0502, P0506, P0507, P2110, P2195, and P2196 are not set.

•One of the following conditions is met: ◦The ignition is off for greater than 12 hours.

ENGINE CONTROLS & FUEL - 1.6L - DTC P0324 TO P0651 -2007 Chevrolet Aveo

•The ignition 1 voltage is between 11-16 volts.
•The barometric pressure (BARO) is greater than 72 kPa.
•The start-up ECT and start-up IAT are between 4-34 °C (39-93 °F).
•The start-up IAT is 3 °C (37 °F) less than the actual IAT.
•The purge enable time is less than pre-determined value based on startup ECT.
•The fuel level is between 6-93 percent.
•The engine run time is between 1-360 seconds plus purge enable time.
•The restricted path test time is completed in less than 220 seconds.
•The DTC run once an ignition cycle when the above conditions are met.

CONDITIONS FOR SETTING THE DTC

•The fuel tank pressure is greater than 8 inches H2O at cold engine startup.
•The above condition is present for at least 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
DTC P0446 is a Type A DTC.

CONDITIONS FOR CLEARING THE DTC
DTC P0446 is a Type A DTC.

DIAGNOSTIC AIDS
REFERENCE INFORMATION
Schematic Reference Evaporative Emissions Hose Routing Diagram


http://www.2carpros.com/forum/automotive_pictures/188069_07aveo_EVAP_1.jpg



Description and Operation:

Evaporative Emission Control System Description

DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP vent valve inlet or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem.

ENGINE CONTROLS & FUEL - 1.6L - DTC P0324 TO P0651 -2007 Chevrolet Aveo

•Scan Tool Data List (w/Throttle Actuator Control)
•Scan Tool Data Definitions (w/Throttle Actuator Control)
•Scan Tool Output Controls (w/Throttle Actuator Control)

Special Tools Required
•J 41413-SPT High Intensity White Light. See Special Tools .
•J 41413-VLV EVAP Port Vent Fitting Tool
•J 41413-200 Evaporative Emissions System Tester (EEST). See Special Tools .
•J 41413-300 EVAP Cap and Plug Kit. See Special Tools .
•GE-41415-50 Fuel Tank Cap Adapter. See Special Tools .
•J 23738-A Vacuum Pump

CIRCUIT/SYSTEM VERIFICATION W/SERVICE BAY TEST

CIRCUIT/SYSTEM VERIFICATION W/O SERVICE BAY TEST

CIRCUIT/SYSTEM TESTING
REPAIR PROCEDURES

1.Verify the EVAP system using the EVAP Service Bay Test. DTC P0446 should not set.
2.If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

1.Ignition ON, observe the DTC information with a scan tool. Verify DTC's P0443, P0452, P0453, P0458, P0459, P0498, or P0499 are not set. â—¦If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
2.Observe the scan tool fuel tank pressure (FTP) sensor pressure parameter. Verify the FTP sensor pressure parameter is near 0 in H2O.
3.If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

1.Ignition OFF, remove the fuel tank filler cap. 2.Ignition ON, observe the scan tool fuel tank pressure sensor voltage parameter. Verify the FTP sensor voltage parameter is less than 4 volts. â—¦If greater than 4 volts refer to DTC P0452 or P0453. 3.Start the engine. With a scan tool seal the EVAP system using the EVAP purge seal function. Command the purge open to 20 percent. Seal the system at -8.00 in H20. Exit the system seal. Verify the FTP sensor pressure parameter decreases to 0 in H2O. â—¦If the scan tool FTP sensor parameter does not decrease, check for a blockage or restrictions in the EVAP vent hose, or replace the EVAP vent solenoid valve.

ENGINE CONTROLS & FUEL - 1.6L - DTC P0324 TO P0651 -2007 Chevrolet Aveo

Evaporative Emission Canister Vent Solenoid Valve Replacement

REPAIR VERIFICATION W/SERVICE BAY TEST
Verify the EVAP system repair using the EVAP Service Bay Test

REPAIR VERIFICATION W/O SERVICE BAY TEST

1.Start the engine.
2.With a scan tool seal the EVAP system using the EVAP purge seal function.
3.Command the purge open to 20 percent. Seal the EVAP system at -8.00 in H20. 4.Exit the system seal. 5.Verify the scan tool FTP sensor pressure parameter decreases to near 0 in H2O.

Obxautomedic
Sep 22, 2010.
Hi! I received your e-mail the other day and really could not do any of it except the first part about cleaning and checking for kinks in the EVAP hoses. I was looking for some possible simple fix so I would not have to take it to the dealer to determine what the problem was. I went to look at the EVAP system & couldn't find it & went to get a Haynes manual & they haven't made them yet. I fould some hoses near the gas tank but i'm not sure if they are with the EVAP system or not. I did notice that when I tried to start the car, it was turning over slow. I took it to Advance to get the battery checked & found that it has a bad battery. The gentleman that helped me checked the code again and said that it could be the gas cap causing the code. I got a new battery & gas cap yesterday and have not had a repeat of the code yet and the car is running fine. I don't feel that you answered the question to my satisfaction & I ended up solving the problem on my own. How do I go about getting a refund on the donation. I appriciate you trying to answer my question but it was not what I was looking for.

Tiny
Cbvet57
Sep 25, 2010.
I am sorry if I didn't answer to your satisfaction.

Hope all it was was the Gas Cap.

I will notify Management that you would like a refund.

.

Obxautomedic
Sep 25, 2010.
We have refunded your donation. I hope we can help you next time.

2CarPros Mike
Sep 25, 2010.